30th June 2013 SAR Formation Flying Annex 7. Orbit Modelling and Analysis, Simulated Mission Planning Document Version: V01_00 Dr Li Qiao Australian Centre for Space Engineering Research (ACSER) University of New South Wales, Sydney, 2052, Australia Revision History Version No. Date Author Description of Change V01_00 30th June 2013 Dr Li Qiao Initial Release TABLE OF CONTENT 1. EXECUTIVE SUMMARY .................................................................................................................... 8 2. INTRODUCTION ............................................................................................................................. 10 3. MISSION APPLICATION REQUIREMENTS....................................................................................... 12 3.1. Soil Moisture Monitoring of Murray Darling Basin (MDB) ................................................... 12 3.2. Power System Requirements ................................................................................................ 12 3.3. Orbit Lifetime ........................................................................................................................ 12 4. ORBIT SELECTION FOR GARADA.................................................................................................... 14 4.1. Orbit Definition ..................................................................................................................... 14 4.2. Orbit Type ............................................................................................................................. 15 4.2.1. Sun-Synchronous Orbits ................................................................................................ 15 4.2.2. Circular and Frozen Orbit .............................................................................................. 15 4.2.3. Repeating Ground Track Orbit ...................................................................................... 16 4.3. Classical and Perturbed Orbit ............................................................................................... 17 4.4. Eccentricity, Perigee Location, Inclination and LTAN Selection ............................................ 18 4.4.1. Eccentricity .................................................................................................................... 18 4.4.2. Perigee Location ............................................................................................................ 18 4.4.3. Inclination ..................................................................................................................... 18 4.4.4. Equator Crossing Time .................................................................................................. 18 4.5. Orbit Altitude ........................................................................................................................ 19 4.5.1. Swath and SSO Repeating Cycle .................................................................................... 21 4.5.2. Instrument Requirements and Orbit Selection ............................................................. 22 4.6. Proposed Orbit Summary...................................................................................................... 26 5. ORBIT FORCE ANALYSIS ................................................................................................................. 27 5.1. Garada Orbit ......................................................................................................................... 27 5.2. High Precision Orbit Propagator ........................................................................................... 28 5.3. The Standard HPOP Settings ................................................................................................. 29 5.4. Central Body Gravity ............................................................................................................. 30 5.4.1. Gravity Models .............................................................................................................. 30 5.4.2. Maximum Degrees and Orders ..................................................................................... 31 5.4.3. Solid Tide ....................................................................................................................... 33 5.4.4. Ocean Tide .................................................................................................................... 33 2 V01_00 Annex 7. Orbit Modelling and Analysis, Simulated Mission Planning 30th June 2013 5.5. Atmospheric Drag ................................................................................................................. 34 5.5.1. Atmospheric Density Models ........................................................................................ 34 5.5.2. SolarFlux/GeoMag ........................................................................................................ 35 5.6. Third Body Gravity ................................................................................................................ 36 5.7. Solar Radiation Pressure ....................................................................................................... 37 5.8. Propagator Integrator ........................................................................................................... 38 5.9. Orbit Force Analysis Summary .............................................................................................. 39 6. LAUNCH VEHICLE SELECTION ........................................................................................................ 40 6.1. Launch Vehicle Selection Criteria .......................................................................................... 40 6.1.1. Reliability of Launchers ................................................................................................. 40 6.1.2. Performance and Suitability of Launchers .................................................................... 41 6.1.3. Launcher Price ............................................................................................................... 41 6.1.4. Availability and Schedule .............................................................................................. 41 6.1.5. Technology Transfer Safeguards ................................................................................... 42 6.1.6. User Relations and Partnerships ................................................................................... 42 6.1.7. Terms and Conditions ................................................................................................... 42 6.2. Satellite Launch System ........................................................................................................ 42 6.2.1. Space Rocket Launch Sites ............................................................................................ 42 6.2.2. Space Rocket Launch Vehicle ........................................................................................ 43 6.2.3. Falcon-9 Performance ................................................................................................... 44 6.3. Backup Launch Vehicles ........................................................................................................ 47 7. ANALYSIS TOOLS ........................................................................................................................... 48 8. APPENDIX ...................................................................................................................................... 49 8.1. List of Launch Vehicles .......................................................................................................... 49 8.2. Small Satellite Orbit Lifetime Analysis .................................................................................. 51 8.2.1. Method for Lifetime Prediction .................................................................................... 52 8.2.2. Sensitivity of Lifetime to Design Parameters ................................................................ 52 9. REFERENCES .................................................................................................................................. 56 3 V01_00 Annex 7. Orbit Modelling and Analysis, Simulated Mission Planning 30th June 2013 LIST OF TABLES Table 1 Sun-synchronous orbit altitude vs. repeat cycles. ................................................................... 20 Table 2 Swath [km] vs. out incidence angle at various orbit height (Inner Incidence angle = 8 deg). 22 Table 3 SSOs and their coverage percentage over MDB. ..................................................................... 22 Table 4 Garada satellite orbit characteristics. ...................................................................................... 26 Table 5 Common propagators and descriptions. .................................................................................. 29 Table 6 Default settings for force model. ............................................................................................. 29 Table 7 Gravity models. ........................................................................................................................ 31 Table 8 Atmospheric density models. .................................................................................................. 34 Table 9 Solar shadow model. ...............................................................................................................